# Fast localization of coalescing binaries with a heterogeneous network of advanced gravitational wave detectors

## TL;DR

This paper proposes a hierarchical method for rapid sky localization of coalescing binaries using a heterogeneous gravitational wave detector network, improving localization accuracy by leveraging less sensitive detectors.

## Contribution

It introduces a hierarchical approach that optimally uses data from detectors with varying sensitivities to enhance localization speed and accuracy.

## Key findings

- Localization accuracy improves by about a factor of 3 with the proposed method.
- Using a lower SNR threshold in the less sensitive detector enhances detection efficiency.
- The approach is effective when the less sensitive detector's sensitivity is about one third of the most sensitive detectors.

## Abstract

We present the expected performance regarding fast sky localization of coalescing binaries with a network of three gravitational wave detectors having heterogeneous sensitivities, such as the LIGO-Virgo network. A hierarchical approach can be used in order to make an effective use of information from the least sensitive detector. In this approach, the presence of an event seen in coincidence in the two more sensitive detectors triggers a focused search in the data of the third, less sensitive, detector with a lower signal-to-noise ratio (SNR) threshold. We investigate the benefit for sky localization that can be expected in such an approach, using simulated data and signals. We find that as the sensitivity of Virgo approaches one third of the LIGO sensitivity, the accuracy and precision of the localization can be improved by about a factor 3 when Virgo data are searched with an SNR threshold around 3.5.